Grid Tie In Solar Systems – Advantages And Disadvantages

For people planning to install photovoltaic (PV) panels in or on their homes to create electricity there are two  approaches to take. You can cut yourself off from the utility companies that supply most homes with electricity. This is known as going off grid and you are completely responsible for providing electricity to your home. If the sun doesn't shine or you have a cloudy few weeks then you have a problem. Or rather, you have thought about this before hand and have a number of back up systems or contingency plans. As you can imagine, an off the grid system can be quite complex and require a fair amount of your time to run and maintain. The other alternative is to remain tied to your utility company and run a solar system at the same time. In effect, the utility company becomes your back up system if the sun doesn't shine enough. Systems like these are known as grid tie in solar systems. This article will cover the advantages and disadvantages of such systems.

So, the first advantage of grid tie solar systems is that they are a good way to use renewable energy without taking on all the responsibility. They are how most people start out when they decide to get a solar power system (approximately 72% of the solar power systems in residential homes are grid tie systems).

Another advantage is known as net metering. Many States have passed laws whereby utility companies must offer residential and non residential properties with PV solar systems an option to interconnect to the utility company. Each state has different criteria, including the amount of Watts produced by the solar system, before a system is eligible. These criteria change all the time as more people use solar panels and the size of the systems get bigger.

Net metering effectively means that any electricity that you produce is credited to your next utility bill. So if you produce more electricity than you actually use, then you will save money on your utility bills. To this extent, people are actually getting bigger systems than they will need so that they can sell electricity to the utility companies. This makes a system more affordable in the long term.

There is more emphasis on utility companies to produce energy from renewable resources. Many States are adopting policies that set targets for utility companies. For instance, New Hampshire’s Electric Renewable Portfolio Standard, enacted in May 2007, requires electricity providers to use renewables for 23.8% of retail electricity by 2025. This may seem a long way off but it will mean that future policies for most utility companies will include creating solar power or buying it off smaller producers through interconnection.

The only downside of a grid tie solar system is that you are still reliant on a utility company for your energy. Even though you produce electricity from your solar panel, this is directed to the utility company before you ever use it. This may seem at odds with the whole point of installing a renewable energy system for your home and if there are power outages then your home will be left in darkness.

One solution to this is to have a grid tied battery backup system. It is more complicated, but effectively, the battery bank is charged by the solar panels. When it becomes fully charged, the excess is sent to the utility company. The batteries can then supply power should there be an interruption in the utility supply.